Rename wasi-base to wasi-cli-base. (#171)

This is just a rename, and it's not yet clear what shape wasi-cli-base
will ultimately take, but for now, it's useful to avoid confusion about
whether wasi-base is meant to be used by all WASI worlds. It is a base
for CLI-like worlds that have command-line args, environment variables,
and exit statuses, and not all WASI worlds will have those.

test-programs/reactor-tests/wit/deps/wasi-cli-base

@@ -0,0 +1 @@
+../../../../wit/deps/wasi-cli-base

test-programs/reactor-tests/wit/test-reactor.wit

@@ -1,10 +1,10 @@
 default world test-reactor {
 
-  import environment: wasi-base.environment
+  import environment: wasi-cli-base.environment
   import streams: io.streams
-  import preopens: wasi-base.preopens
+  import preopens: wasi-cli-base.preopens
   import filesystem: filesystem.filesystem
-  import exit: wasi-base.exit
+  import exit: wasi-cli-base.exit
 
   export add-strings: func(s: list<string>) -> u32
   export get-strings: func() -> list<string>

wasi-common/src/wasi/mod.rs

@@ -11,9 +11,9 @@ wasmtime::component::bindgen!({
       import random: random.random
       import poll: poll.poll
       import streams: io.streams
-      import environment: wasi-base.environment
-      import preopens: wasi-base.preopens
-      import exit: wasi-base.exit
+      import environment: wasi-cli-base.environment
+      import preopens: wasi-cli-base.preopens
+      import exit: wasi-cli-base.exit
       import console: logging.handler
       import default-outgoing-HTTP: http.outgoing-handler
     ",